Missile launch control system

ABSTRACT

A control system for launching missiles from aircraft wherein said missiles are automatically prepared and fired in either an individual or ripple fire sequence, particularly embodying logical mechanisms for arming and firing said missiles in predetermined sequence, including the arming and firing of said missiles in an alternate sequence when individual missiles are missing from their firing positions.

ilnite States Patent 1191 Langlois et al.

[4 1 May 29, 1973 MISSILE LAUNCH CONTROL SYSTEM Inventors: Leo O. Langlois; Ralph T. Tadaki, both of Los Angeles; John R. Ellis, Jr., Thousand Oaks, all of Calif.; R'oy W. Stevens, Jr.; Robert H. Leech, both of Tucson, Ariz.

Assignee: Hughes Aircraft Company, Culver City, Calif.

Filed: Dec. 10, 1970 Appl. No.: 97,452

U.S. Cl ..89/l.8l4, 89/l.8l2 Int. Cl. ..F4lf 3/04 Field of Search ..89/1.8, 1.814, 1.815,

[56] References Cited UNITED STATES PATENTS 3,598,015 8/1971 Delistovich ..89/1.814 3,453,496 7/1969 Wright et a1.... ..89/1.814 3,064,537 11/1962 Baller et a]. ...89/1.814 X 3,499,363 3/1970 Lauro ..89/l.814 X Primary ExaminerSamuel W. Engle Attorney-W. H. MacAllister, Jr. and D. C. Keaveney [5 7 ABSTRACT A control system for launching missiles from aircraft wherein said missiles are automatically prepared and fired in either an individual or ripple fire sequence, particularly embodying logical mechanisms for arming and firing said missiles in predetermined sequence, including the arming and firing of said missiles in an alternate sequence when individual missiles are missing from their firing positions.

4 Claims, 14 Drawing Figures MISSILE LAUNCH CONTROL SYSTEM BRIEF DESCRIPTION OF THE PRIOR ART This invention pertains to the logical control of arming and firing, in sequence, missiles, particularly from an aircraft, and particularly in air-to-air combat.

In the past it has been necessary not only to arm a particular missile prior to firing, but also to re-arm said missile if said missile was not fired within a predetermined time after arming. Such missiles tended to get excessively hot if left in their armed condition.

With advances in the electronic arts wherein the generated heat is reduced, and alterations in the tactical mission of the missile whereby only a portion of the electronics is energized prior to missile firing, a new control system, such as the one contemplated by this invention, has been conceived.

The procedure of preparing and arming two separate missiles so that the missiles could rapidly be fired in succession, such firing being called ripple fire, required the control and careful attention of the pilot of the supporting craft to determine that two particular missiles were ready for firing and to keep track of those missiles so that at least one of the missiles did not automatically shut down before the pilot was ready to fire.

Further, in prior systems, the pilot was required to keep track of his inventory of missiles so that he always selected a missile, actually in the rack on the pylon, for arming and firing.

It may be seen, where the pilot must react within seconds of detection of the target, that the simultaneous flying of the aircraft and making decisions regarding which missile to fire, as well as following a particular procedure to arm and then to re-arm such missile, resulted in substantial jeopardy and actual casualties to the craft either from enemy fire or from placing the craft out of an advantageous position while attention of the pilot was diverted to the care and proper cycling of the missiles.

BRIEF DESCRIPTION OF THE INVENTION The apparatus contemplated by this invention is a logical mechanism which is designed automatically to prepare and fire, in sequence if desired, a predetermined number of missiles, usually one missile on each pylon, at a time. The apparatus is shown herein both as electrical-mechanical switching apparatus, and also electronic, and particularly semiconductor, switching apparatus which may be used conveniently to replace the electromechanical switches. Further, such replacement is desirable because of the relatively low power required by semiconductor devices, their fast switching times, and their relative insensitivity to acceleration of the supporting craft.

The apparatus of this invention, upon the mere pressing of a button or the like, arms a first missile upon one of the pylons. Then immediately upon selection of a second missile upon another pylon, the second missile is armed automatically. When the trigger is pressed, the second selected missile is fired, then the selecting switch automatically indexes to the first pylon where the logical circuitry of this invention selects the armed missile. When the trigger is pressed again, the armed missile on the first pylon is launched.

In a preferred embodiment of this invention, each of two pylons carries two missiles. If a particular missile on a particular pylon is selected, and if that missile is missing, the other missile on that pylon is automatically selected upon arming. In the typical situation only one missile on each pylon is armed at any one time. When the trigger is pressed, if the trigger signal is directed to an unarmed missile, the apparatus of this invention automatically directs it to an armed missile on that particular pylon and fires the armed missile.

If an arm" signal is directed to a particular missile and the missile is missing, the other missile on that pylon automatically receives the arm signal and is armed, making it ready for firing.

It is therefore an object of this invention automatically to prepare, arm, and fire missiles from at least a pair of missile stations.

It is another object of this invention, automatically to sense the absence of a missile and to redirect arm and trigger signals to the remaining missiles.

It is still a more particular object of this invention to direct firing signals, which are channeled to a particular pylon, to a missile which is armed on that pylon.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects will become apparent from the following description, taken in connection with the accompanying drawings:

FIG. 1 is a front profile view of a typical fighter aircraft showing two pylons, each of which carries a pair of missiles;

FIG. 2 is a diagram of a preferred embodiment of the invention, using gates to mechanize at least a portion of the logic equations of the invention;

FIG. 3 is a more detailed diagram of a preferred mechanization of one set of electronic controls of FIG.

FIG. 4 is a switching diagram of a typical system of this invention;

FIG. 5 is a switching diagram of the mechanization of the LS, RS, and PS relays of one set of controls of FIG.

FIG. 6 is a switching diagram of the mechanization of the R, RSL, L, LSL, and Q relays of one set of controls of FIG. 4;

FIG. 7 is a switching diagram of the mechanization of the ARM relay of one set of controls of FIG. 4;

FIG. 8 is a switching diagram of the mechanization of the TR relay of one set of controls of FIG. 4;

FIG. 9 is a switching diagram of the mechanization of the B relay of one set of controls of FIG. 4;

FIG. 10 is a switching diagram of the mechanization of the ready lite of one set of controls of FIG. 4;

FIG. 11 is a switching diagram of the mechanization of the C relay of one set of controls of FIG. 4;

FIG. 12 is a swtiching diagram of the mechanization of the TRX relay of one set of controls of FIG. 4;

FIG. 13 is a switching diagram of the mechanization of the RT relay of. one set of controls of FIG. 4;

FIG. 14 is a switching diagram'of the mechanization of the LT relay of one set of controls of FIG. 4;

DETAILED DESCRIPTION OF THE INVENTION In FIG. 1 is shown an aircraft, A, with four missiles, l, 2, 3, and 4, mounted upon two pylons or missile stations, 5 and 6. Although the invention is shown with two pylons having two missiles each, it is obvious that the invention can be extended to more pylons and/or each pylon having more than two missiles. Two missiles and two pylons are shown herein for illustrative purposes only.

Pylon is on the starboard wing of the aircraft, A. Missile 1 is designated the inboard or left missile of the right pylon. Missile 2 is designated the inboard or right missile on the left pylon. Missile No. 3 is designated the lower or right missile of the right pylon. Missile No. 4 is designated the lower or left missile of the left pylon.

The mechanism of this invention comprises logical mechanisms which are adapted to arm and fire the missiles 1, 2, 3, 4. Because they are logical mechanisms, logical equations may be written, and the logical equations may be mechanized by electronic mechanisms such as electronic gates and counters or steppers; or the mechanism which expresses the logic equations may be shown as mechanical switches. The applicants have elected to describe their invention first in terms of gates, then in terms of mechanical switches.

The details of arming and firing of the missile itself, such as firing a cooling squib, and igniting the rocket have been omitted herein, for such mechanisms are within the state-of-the-art.

In an embodiment expressed in FIGS. 2 and 3, the voltage source 200 is a common power source which is assumed to be ready prior to the described operation of the circuit. To that end, time delay mechanisms (not shown), and the like may be used to prevent the drawing of current from source 200 until source 200 has become sufficiently stable. Typically, for example, source 200 becomes stable within three seconds of the time that it is turned on.

It is also important to note that the power supply 200 may have portions delivering negative as well as positive voltages. It may also have isolated ungrounded portions, as required.

In addition to an on-off switch (not shown), the pilot has in his cockpit three switches: switch 202 which is called the select switch, switch 204 which is called the arm-safe switch, and switch 206 which is the trigger. The trigger 206 is typically placed on the handle of the control stick of an aircraft. The select switch 202 and the arm-safe switch are preferably placed in a console (not shown).

The stepper 212, which may be, for example, a ring counter, receives stepping signals from OR gate 208 each time the select switch 202 is energized. When switch 204 is in its arm position, the pressing of the trigger 206 also channels a signal, through AND gate 210 and OR gate 208 to the input of the stepper 212. Typically, the turning on of the power source 200 sets the stepper (by means not shown) into its position No. 1. Additional signals through gate 208 cause the stepper 212 consecutively to step through conditions whereby its output terminals are set to a high" signal in the order l-2-3-4-l-. The signals are delivered from stepper 212 to two identical sets of electronics 234 and 236 so that the firing order, in the example given, is in the same sequence as the sequence of the stepper 212, i.e., right pylon, left or inboard missile; left pylon, right or inboard missile; right pylon, right or lower missile; left pylon, left or lower missile; right pylon, left or inboard missile The two sets of electronics 234 and 236 are shown in FIG. 2 with only those internal components which connect to external apparatus. The internal components of the right pylon electronics 234 and the left pylon electronics 236 are numbered the same except that the components of the left pylon electronics have a suffix A. The signals from stepper 212 pertaining to the right pylon missiles, i.e., missiles 1 and 3, are delivered to the right pylon electronics 234. The signals from stepper 212 pertaining to the left pylon missiles, i.e., missiles 2 and 4 are delivered to the left pylon electronics 236.

When the pilot has set the arm-safe switch 204 into the arm position, the arm signals are delivered to both sets of electronics 234 and 236. More particularly, such signals are delivered to the ARM gates and 135A. When the arm-safe switch 204 is turned to the safe" position, the signal from switch 204 is removed from the input of ARM gates 135 and 135A, thereby starting a sequence of events which places each system in a safe condition.

The trigger switch 206 preferably has a spring (not shown), and the pilot must then pull the trigger against the urge of the spring. The pulling of the trigger, and thereby the closing of the trigger switch 206 is ineffective unless the arm-safe switch 204 is in the arm" position, whereby gate 210 delivers a signal to gate 208 and thence to stepper 212, and delivers a signal to the TR gates 103 and 103A in the two electronic systems 234 and 236.

When one of the missiles on the right pylon has been selected by the stepper 212, i.e., missile 1 or missile 3, the signals from stepper 212 are delivered to OR gate 101, thereby generating a signal PS (or pylon select) in the right pylon electronics indicative of the fact that a missile on the right pylon has been selected. Similarly, when missiles 2 or 4 are selected by the stepper 212, gate 101A is energized and a signal PS in left pylon electronics is generated. When missile N0. 1 is selected, the stepper signal No. l is delivered not only to OR gate 101, but also to OR gate 107. Similarly, the signal No. 3 from stepper 212 is delivered not only OR gate 101, but also OR gate 1 17. The signal No. 2 from stepper 212 is delivered to not only OR gate 101A, but also to OR gate 117A. The signal No. 4 is delivered from stepper 212 not only to OR gate 101A, but also to OR gate 107A.

The select lights 226, 228, 230, and 232 are in the cockpit where the pilot may readily see them. The select light 226 is controlled in response to the LS signal from AND gate 131, indicative that the left missile of the right pylon, or the No. l missile, has been selected. The select light 228 is controlled in response to the signal RS from AND gate 121A, indicative of the fact that the right missile of the left pylon, or missile No. 2, has been selected. The light 230 is controlled in response to the signal RS from AND gate 121, indicative of the fact that the right missile of the right pylon, or missile No. 3, has been selected. The light 232 is controlled in response to the signal LS from AND gate 131A, indicative of the fact that the left missile of the left pylon, or missile No. 4, has been selected.

The timing sequences in the two sets of electronics may conveniently be divided into A time during which the power supplies are warming up, the aircraft is taking off, the wheels of the aircraft are being raised, and the systems of the aircraft, in general, are being made ready for combat. If, during this period, the switch 204 remains in its safe position, the position of stepper 212 is of no consequence. When, however, switch 204 is switched to its arm condition, the second major time segment, called B time commences. A gate, such as AND gate of FIG. 3 becomes energized, and a missile, selected as hereinafter described, is prepared for firing, In a typical missile, the sequence for preparing the missile for firing may take, for example, on the order of 3 seconds. The three second delay mechanisms 109 and 109A are adapted to introduce delay into the B signal of the proper length to allow the missile to arm itself properly prior to the time of the application of the firing signal. Should the required time delay be more or less than the 3 second delay indicated, the block represented by the symbols 109 and 109A would be modified to reflect that change. Three seocnds, in the example given, after obtaining the B signal, the output of the delay mechanism 109 delivers a signal to the pylon ready light 222 or 224 indicating that the particular pylon has an armed missile which is ready for firing.

C time" occurs after the trigger 206 is actuated upon the closing of the C gate. The actual firing control is not shown, but is actuated by the gate 187 (FIG. 3).

Q time occurs when Q signal appears at gate 177 (FIG. 3) which shuts down the entire select, preparation and firing circuitry.

Each of the missiles has thereon means porducing a signal, 214, 218, 216 or 220 for producing a signal indicative of the presence or absence of that missile. In a preferred embodiment, one merely grounds a contact in response to presence of a missile. The absence of ground contact indicates that the missile is missing. The presence or absence of the missile, and therefore the presence or absence of the missile signal is then used in the logic of this invention to transfer arming and trigger signals automatically from a designated missile (which is missing) to the other missile on that particular pylon without the intervention of the pilot. The logical mechanism for achieving this result will be described below, particularly in connection with FIG. 3. It will also be described in detail in connection with mechanical switching diagrams which follow FIG. 3.

The presence of missile No. 1 places the link 214 into the circuit, thereby delivering a signal to the input to gates 169 and 127. Similarly, the presence of missile No. 3 causes link 218 to be in place and a signal to be delivered to the inputs of AND gates 119 and 183. The presence of missile No. 4 causes a signal to be delivered to the input of AND gates 169A and 127A, and the presence of missile No. 2 causes a signal to be delivered to the inputs of AND gates 119A and 183A.

Because the electronics 234 and 236 are identical, it is only necessary to describe the entire block of electronics once. Additional electronics (not shown) may also be within the actual box which is positioned upon the pylon. These additional electronics (not shown) include such items as timing circuits which are controlled by the outputs of some of the gates, and the like, of FIG. 3, and which control the delay circuits of FIG. 3. They also include such items as mechanisms for starting the cooling cycles within the missiles, mechanisms for starting infrared or radar tracking systems within the missiles, mechanisms for firing the missiles, and the like.

FIG. 3 mechanizes the equations set forth in Table 1.

TABLE I PS (Select left msl) (select right msl) TR (arm switch)(trigger switch) (PS) (B delayed by 3.0 seconds) L (m) (left missile in place) R m (right missile in place) L S= [(Select left msl) (select rt msl) (ARM)] (L) R S= [(Select rt msl) (select lft msl) (ARM)] (R) LSL= (lft msl in place) [(TR 3 sec) (LT) LSL] RSL (rt msl in place) [(TR 3 sec) (RT) RSL] TRX= (TR 1 sec delay) (TRX) (PS) ARM (PX) (m) (R RT L LT) (ARM SWITCH) RT= RS (RT) B LT LS (LT) B Q= (TR+ 3.0 sec.) (B) (Q) (PS) (.8) (ARM (C) RDY LITE B 3 sec.

In Table I, select left missile or select right missile refers to the signal from stepper 212 as compared to the signal from AND gate 131 and AND gate 121 which are the LS and RS signals, respectively. The term arm switch refers to a signal from switch 204 when switch 204 is in its arm position as compared to the ARM signal which is generated by AND gate 135. The phrase B delayed by 3 seconds, B plus 3 seconds means, for example, the signal at the output of the 3 second delay means 109 which appears three seconds after the signal at the output of AND gate 145. The phrase trigger switch refers to the signal at the output of gate 210 of FIG. 2 rather than the trigger signal TR which appears at the output of AND gate 103.

The PS signal at the output of OR gate 101 is indicative of the fact that that particular pylon has been selected and the inputs of gate 101 are connected to be responsive to signals from stepper 212 indicative of the fact that one or the other of the two missiles, on that particular pylon where the particular electronics of FIG. 3 is, has been selected. The remainder of the description of FIG. 3 will be as if the right pylon electronics were being described. With that assumption, a signal PS appears whenever missiles No. 1 or 3 are selected.

A signal L at the output of AND gate 127 is indicative of the fact that there is a left missile in place on that particular pylon (on the right pylon, this would mean that the link 214 is in place,) and, also that there is no left select lock-out signal, LSL. The inverting amplifier 129 is connected to produce a signal which is the logical inverse, L, of the L signal at the output of AND gate 127.

The output of AND gate 131, LS, appears when the left missile on the particular pylon has been selected, an LS signal appears when an L signal and appears at the output of gate 127, a right transfer, RT, signal does not appear at the output of Gate 153, and either the left missile, No. 1, signal appears at the output of stepper 212 or the right missile signal, No. 3, appears at 212 together with the ARM signal from gate 135. v

The ARM signal appears at the output of AND gate when switch 204 in the cockpit of the aircraft (FIG. 2) is in its armed position, and when one of the two missiles has been selected, as indicated by the presence of a PS signal, and when the double firing signal TRX does not appear at the output of gate 147, and when OR gate 133 delivers a Signal to gate 135. Gate 133 delivers a signal to gate 135 whenever a right transfer signal, RT, appears at the output of OR gate v153, or when the left transfer signal, LT, appears at the output of OR gate 159, or when signal R does not appear at the output of gate 119 or when the signal L does not appear at the output of gate 127.

A signal, R, appears at the output of AND gate 119 when (for example on the right pylon), link 218 is in place, and no "right select lockout signal, RSL, ap pears at the output of AND gate 183. The inverting amplifier 120 produces a signal, R.

A right select signal, RS, is produced at the output of AND gate 121 when an R signal is produced by gate 119, and a left transfer" signal, LT, is not produced by OR gate 159, and either missile No. 1 is selected by stepper 212 or missile No. 3 has been selected and an ARM signal is produced by gate 135.

A left select lockout signal, LSL, occurs when the left missile is in place (link 214 is closed), and three seconds after the TR signal appears at the output of AND gate 103 the left transfer" signal, LT is present at the output of gate 159. The LSL signal holds as long as the left missile remains in place.

A right select lockout signal, RSL, occurs when the right missile is in place (link 218 is closed), and three seconds after the TR signal appears at the output of AND gate 103 the right transfer" signal, RT, is present at the output of gate 153. The RSL signal holds as long as the right missile remains in place.

A double fire lockout signal TRX appears at the output of OR gate 147 one second after a trigger signal, TR, appears at the output of AND gate 103. The TRX signal is held as long as the right pylon remains selected, as indicated by the presence of a PS signal.

A trigger signal, TR, appears at the output of AND gate 103 when switch 204 is in its armed position, and the trigger switch 206 is energized, producing a signal at the output of AND gate 210, and a pylon select signal PS appears at the output of gate 101, and three seconds after the B signal at the output of AND gate 145.

A B signal appears at the output of AND gate 145 a shutdown" signal, 0, does not appear at the output of OR gate 177, and an ARM signal appears at the output of gate 135, and either an LS signal appears at the output of gate 131 or an RS signal appears at the output of gate 121. The B signal is held on until a signal appears.

The C-time" signal C appears at the output of AND gate 187 when the TR signal appears at gate 103, and the B signal appears at gate 177. The C signal is held until the shutdown signal Q appears.

A right transfer" signal, RT, appears at the output of OR gate 153 whenever an RS signal appears at gate 121. The RT signal is held by the B signal if the electronics is in B or C time, i.e., ifa missile is armed or firing from that pylon.

A left transfer" signal, LT, appears at the output of OR gate 159 whenever an LS signal appears at gate 131. The LT signal is held by the B signal if the electronics is in B or C time, i.e., ifa missile is armed or firing from that pylon.

The presence of an LS signal lights the select light 226, indicating that missile No. l is selected. The presence of an RS signal lights the select light 230, indicating that missile No. 3 is selected.

Three seconds after a B signal appears, the ready light 222 is lighted, indicating that a missile upon the right pylon is armed and ready for firing.

The inverting amplifiers 120, 129, 161, 163, 151, 171, 179, 185, and 189 produce signals which are the logical inverses of their input signals.

To describe the operation of the mechanism of FIGS. 2 and 3, assume that the aircraft has taken off, the wheels are retracted, and the pilot has turned on the equipment preparatory to its actual operation. Assume further that the initial position of the stepper 212 is on the No. l missile, although it may be seen that this particular choice is not important or critical. The select switch 202 is open, the switch 204 is in its safe position, and the trigger switch 206 is not actuated. The signal from the No. 1 position of stepper 212 causes a signal PS to appear at the output of OR gate 101 and a signal to appear at the output of OR gate 107. There is an L T initially at the input to gate 121. An R signal at gate 1 19 indicates the right missile is in place, but there is no output of gate 117, whereby no RS, and hence no RT signal appears. Because of the presence of the left missile select signal and the presence of an fi signal at the input of gate 131, provided the left missile of the right pylon is in position, thereby closing link 214, a left select signal LS appears at the output of AND gate 131 which lights light 226 indicating to the pilot that missile No. 1 has been selected.

The pilot, by successively operating the select switch 202, directing a signal through OR gate 208 may step the stepper 212 through positions 1, 2, 3, 4, 1 into any position that he desires. If he steps from position 1 to position 2, the RS signal of the left pylon electronics appears and lights light 228. Further indexing of the stepper 212 into its position No. 3 causes the RS signal of the right pylon electronics to appear and light light 230. Stepping to position No. 4 of stepper 212 causes the LS signal of the left pylon electronics to appear and light light 232.

Assume again that the stepper 212 is in position No. 1. Assume, further, that all four missiles are on board the aircraft A, and they are connected to be armed and fired. The links 214, 216, and 218 and 220 are in place. The selecting of the left missile of the right pylon causes the PS signal of the right electronics to appear, and the fact that the link 214 is in place and that the left select lockout signal LSL has not appeared (whereby K has appeared) produces a signal L. The presence ofa signal L and a signal W1" and a signal from No. 1 step of the stepper 212 causes the signal LS to appear. The appearance of LS at gate 159 causes a signal LT to appear, thereby extinguishing the signal FT.

Assume, now, that switch 204 is moved from its safe to its arm position. This applies a signal at the input to ARM gates and 135A. The LT signal from gate 159 is channeled from OR gate 133 to AND gate 135. The PS signal at the output of gate 101 and the signal from switch 204 also appears at the input of gate 135. Because the trigger 206 has not been pressed and the TR gate has not been energized, no TRX signal appears at the output of gate 147, whereby a signal TRX signal appears at the output of gate 151, and the m signal is channeled to the input of AND gate 135 thus producing an ARM signal at the output of gate 135.

The ARM signal from gate 135 is channeled through AND gate 141 and OR gate 143 to the input of AND gate 145. The presence of an LS signal at the output of gate 131 causes a signal at the output of gate 139 which opens 141 allowing the ARM signal to pass therethrough. Because of the absence of a 0 signal at the output gate 177, a 6 signal appears at the output of inverting amplifier 179 and the input to gate 145, opening gate 145 and producing a B signal. The B signal then, in addition to its other functions in the circuit of this invention, starts timing signals to the left missile, thereby arming the left missile. After a three second delay (the three seconds being merely characteristic of a typical missile) the left or No. l missile is armed and ready for firing.

At this point the pilot may index to the other pylon and arm a single missile on the other pylon, or he may fire the armed missile. The pilot has one other choice: he may turn the switch 204 into its safe position thereby disarming the missile he has just armed.

For a manual shutdown, the pilot turns his armsafe switch 204 into its safe position, thereby removing the signal from switch 204 to the AND gate 135 and removing the ARM signal. The removal of the ARM signal causes the inverting amplifier 137 to produce an m signal at the output of inverting amplifier 137. The ARM signal delivered to AND gate 175, together with the B signal, PS signal, and C signal causes a signal to appear at the output of AND gate 175 which is channeled through OR gate 177 producing a Q signal which directs that the system be shut down. The Q signal is also directed to the armed missile which causes the missile to be disarmed. Since the trigger 206 has not been energized, no C signal appears at the output of gate 187 but a C signal appears at the output of gate 189.

If the pilot had decided to fire the armed missile No. l, he would have pressed his trigger 206, with the switch 204 armed which would deliver a signal to the input of time delay 211 and to the inputs of AND gates 103 and 103A. Gate 103A would not produce an output signal because it has no PS and no B inputs. There is a PS input signal to gate 103 and, provided, 3 seconds has passed from the time of the appearance of a B signal (indicating that there is a fully armed missile on the right pylon) an output signal would be produced at the output of gate 103. The TR signal at the output of gate 103 is channeled through OR gate 191 and AND gate 187. The presence of a B signal and a 6 signal at the inputs of gate 187 produces a C signal which, among other things, is channeled to armed missile No. 1 firing it. The C signal is also channeled to the unarmed missile, but additional circuitry (not shown) has lock-out protection which prevents a firing attempt. The C signal is channeled through the OR gate 191 so that after a momentary TR impulse is received, the signal C is held.

The time delay of delay 211 is momentary, being being only long enough to allow the C gate 187 to latch, i.e., to be self-holding by virtue of the channeling of the C signal through gates 191 and 187. It should be noted that the B signal at the output of gate 145 is channeled through gate 143, whereby the B signal is held unitl the 6 disappears, i.e., until a signal appears at the output of gate 177. It should be further noted that a Q signal cannot appear, and the 6 signal at the output of amplifier 179 cannot disappear as long as there is a C signal at the output of gate 187 unless a time delay of 3 seconds has occured after the presence of a TR signal. (The three second delay being more than sufficient for normal firing.)

The delay 211, then, is merely to ensure that the C signal appears before the stepper 212 switches from missile No. l to missile No. 2. The stepping from mis- 10 sile No. 1 to missile No. 2 is caused by this signal from gate 210 through the delay 211 and the gate 208. Because the arm-safe switch 204 is in its armed position, missile No. 2 on the left pylon immediately starts its arming procedure, in a manner identical to that just described for missile No. 1, by the electronics 236. Three seconds later the left pylon ready light turns on, and missile No. 2 is ready to fire.

The pilot may now press the trigger 206, causing the electronics 236, in the manner described in connection with missile No. 1, to fire missile No. 2. The time delay of delay means 211, being very slight, causes stepper 212 almost immediately to index to missile No. 3 which starts arming. After three seconds, missile No. 3 is armed and a further pulling of the trigger 206 causes missile No. 3 to fire by means of the control system of electronics 234, and it causes the stepper 212 to index the missile No. 4. Missile No. 4 may then be fired after allowing three seconds for arming.

The pilot may decide that he wants to arm two missiles simultaneously so that they may be fired in rapid sequence without waiting the 3 seconds for arming. The pilot arms missile No. 1 as described above, but he does not operate the trigger 206. Instead, the pilot presses the select switch 202 causing stepper 212 to index to missile No. 2, whereupon missile No. 2 starts to arm while missile No. 1 remains armed. Further, it should be noted that the pilot need not wait a full three seconds for missile No. 1 to be armed before he presses the select button 202 as long as the arm-safe switch 204 is turned to its arm position before the select switch 202 is cycled. The placing of the arm-safe switch 204 into its arm position almost immediately causes a B signal to appear in the right pylon electronics 2, 3, 4. The B signal, through gate 143 and gate 145 is latched in until the 6 signal disappears. The 6 signal will not disappear unless the missile No. 1 is fired and a 3 second delay after the appearance of a TR signal gate 103, or the arm-safe switch 204 is moved to the safe position while a right pylon missile is selected. Note that the cycling of stepper 212 from the No. 1 to the No. 2 position removes the PS signal from gate thereby removing the ARM signal and producing an ARM signal at the output of inverting amplifier 137. The removal of the ARM signal from gate 141 does not cause the B signal to extinguish because of the feedback loop from the output of gate 145 through gate 143. The delay 174 delays the presentation of the ARM signal to gate 175, whereby the PS signal is removed before the delay ARM signal is applied, and a Q signal is thereby not produced. Thus, the pilot may switch to the No. 2 missile position of stepper 212 by pressing the select switch 202, starting the arming of missile No. 2 before missile No. 1 is fully armed.

With missiles Nos. 1 and 2 arming or armed, the pilot may not arm missiles 3 and 4 before missile 1 and 2,'respectively, are either fired or disarmed.

Assume missiles No. 1 and 2 are either armed or arming, and the pilot presses the select switch 202, thereby stepping the stepper 212 into its missile No. 3 position. Because of the presence of a signal at the No. 3 output of stepper 212, a PS signal appears at the output of gate 101. Neither of the missiles on the right pylon have been fired, whereby no RSL signal is at the output of gate 183, and RSL signal does appear at the output of inverting amplifier which produces, since the right missile is in place and link 218 is thereby in place, a R

output at the output 119. Remembering that missile No. 1 is either armed or arming, gate 145 is producing a B signal which holds LT signal at the output of gate 159. Consequently, an LT signal does not appear at the output of inverting amplifier 161 and no RS signal may appear at the output of 121. Because no RS signal appears at the output of 121, the right missile will not be armed even if an ARM signal appears at the output of gate 135, for the internal circuitry of the missile No. 3 requires the receipt of the RS signal before it will commence arming. In fact, because of the presence of a LT signal at the output of gate 159 and the presence of an arm signal from arm-safe switch 204, and the presence of a TRX signal and a PS signal, an ARM signal appears at the output of gate 135 and is presented at the input of gate 105, whereby the No. 3 signal from stepper 212 is channeled to gate 131. The left missile is still in place and the left select lock-out signal has not appeared, whereby L SL signal is present at the input to gate 127, thereby producing an L signal and a LS signal appears which keeps the control directed to the left missile and keeps the left missile select light (i.e., missile No. 1) lighted when the stepper 212 signal is on missile No. 3 and missile No. 1 is armed or arming.

With missiles No. l and 2 armed and with the stepper 212 in position No. 3, the pilot may decide to rapid-fire the two armed missiles. He need not use the select switch 202 to step through position No. 4 and back to position No. 1 before he fires. instead, he may fire at any particular position of the stepper switch 212 that he desires.

Suppose that the pilot desires to fire the two missiles in rapid sequence when the stepper switch 212 is in its position No. 3. The pilot presses the trigger 206. The signal at the output of gate 210 is delivered to gate 103. Since the stepper is on its position No. 3, a PS signal is appearing at the output of gate 101. Provided a three second delay has occured since the appearance of B signal at the output of gate 145, the right pylon ready light is on, and TR signal appears at the output of gate 103. The TR signal, channeled through OR gate 191 appears simultaneously with the B signal and the 6 signal at the input to gate 187 which actuates and produces a C signal thereby firing the particular missle which is armed, namely the left missile which is receiving a LS signal from gate 131.

After a very short delay, caused by delay 211, to allow the C signal to latch, the output of gate 210 is delivered through gate 208 to stepper 212, thereby stepping stepper 212 into its No. 4 position. With stepper 212 in its No. 4 position of stepper 212 produces not LS signal, but RS signal, and the pilot may immeidiately pull the trigger, thereby establishing a C signal in the left pylon electronics 236 which is directed not to missile No. 4, but to missile No. 2 because of the presence of the LS signal rather than the presence of a RS signal. Further, the pressing of the trigger which fires missile No 2, as soon as the C signal has latched in, is delivered through the relay 211 and gate 208 to stepper 212, stepping stepper 212 into the missile No. 1 position.

Now, with the stepper 212 in the No. 1 position and with the No. 1 missile already fired, and with the armsafe switch 204 in its arm position, the missile No. 3 becomes armed, and after a three second delay for arming, may be fired by pulling the trigger 206. The arming of missile No. 3 is described as follows. With missile No. 1 already fired, link 214 no longer exists, and a L signal does not appear at the output of gate 127. A sig nal PS does appear at the output of gate 101. Because the signal L does not appear, a L at the output of inverting amplifier 129 is channeled through gate 133 and through gate 135. Since the trigger has not been pulled in this cycle, no TR signal has appeared in this cycle and no TRX has appeared in this cycle, whereby a TRX signal is applied to gate 135. With the arm-safe switch in its arm position, gate 135 produces an ARM signal. The presence of the ARM signal at the input of gate 1 15 causes the signal from the No. 2 position of stepper 212 to be channeled through gate and gate 117 into gate 121. Because the firing of the left missile removed the L signal, no LS now exists in the right pylon electronics. Further, after the firing of the missile No. 1, a signal from the 3 second delay circuit 113 causes a Q signal to appear momentarily at gate 177, thereby momentarily extinguishing the 6 signal at the output of inverting amplifier 179 and allowing the LT signal at the output of gate 159 to disappear, producing an LT signal at the output of inverting amplifier 161. The W signal combines with the other inputs to gate 121 to produce an RS signal.

The RS signal is channeled to the right of No. 3 missile. The B signal is reset, which arms the No. 3 missile and, after a three second delay, the right pylon ready light appears and No. 3 missile is ready for firing. When the trigger 206 is pulled, the RS signal channels that trigger signal from the output of gate 210 to generate a C signal which is delivered to the No. 3 missile, firing the No. 3 missile.

In a similar fashion, the No. 4 missile may be armed when the stepper 212 turns to No. 2 position because the No. 2 missile is no longer there and the electronics 236 causes the No. 2 signal to generate an LS signal in the electronics 236.

Further, instead of firing the No. 3 missile when the stepper 212 was in its No. 1 position, the pilot might have pressed the select switch 202 which would step the stepper 212 into its No. 2 position thereby commencing the arming of the No. 4 missile. When the trigger 206 was next actuated, the No. 4 missile would have been fired first, and after a short delay due to the delay circuit 21 1, the stepper 212 would have stepped to the No. 3 missile. The next pull of the trigger 206 would have fired the No. 3 missile.

It is instructive to focus attention on the functions of some of the signals. For example, the LSL and RSL signals are called lock-out signals. The LSL signal appears three seconds after the TR signal is generated at the output of gate 103 provided the left missile is still in place at that time. Assuming that the left missile was the missile which was to be fired, the LT signal is present at the input of gate which causes the 3 second delayed TR signal to set the LSL signal because the left missile is still in place. The LSL signal then maintains itself as long as the left missile remains in place. The LT signal applied to gate 125 stays on momentarily after the three second delay time. The brief holding may be caused, for example, by slowing the rise time of the Q signal at the output of gate 177, whereby the B signal, and consequently the LT signal, are not extinguished until the delayed TR signal is delivered through gates 125, 167, and 169.

Similarly, if it had been the right missile which was recently fired, an RT signal would be present and the delayed TR signal would set the RSL gate 183 if the right missile had failed to leave its launcher. The presence of LSL or RSL signals prevents m and m signals, respectively, and thereby prevents the generation of L signals and R signals and consequent creation of LS and RS signals.

The Q signal remains on only momentarily. The pilot holds the TR signal on for only a short time. That short pulse is then transmitted, after a delay of three seconds after the signal appears at the output of gate 103, through gate 177. The presence of a Q signal extinguishes the 6 signal which shuts off the B signal which shuts off the C signal and which shuts off the holding loop of the Q signal.

The TRX signal is merely the TR signal delayed, for example, l second. It prevents the arming and firing of two missiles on the same pylon if the pilot neglects to release the trigger. Thus, it might be called a doublefire lock-out signal. Note, for example, that the Til X signal is applied to gate 135, and must be present for the ARM signal to be present. Thus, 1 second after the TR signal, not only the TRX signal appears, but also the ARM signal disappears. The TRX signal is then held by the PS signal until stepper 212 makes a step to a position corresponding to a missile on the other pylon, at which time the PS signal disappears and so does the TRX signal, cuasing the TRX to reappear and allow the ARM signal to reappear the next time a missile on that particular pylon is selected.

The above discussion of the apparatus of FIGS. 2 and 3 is directed, primarily, to the use of electronic apparatus, although the gates may be interpreted as mechanical switches.

it is important to demonstrate an embodiment of the invention using switching circuits. FIGS. 4 through 14 are directed to such an embodiment.

FIG. 4 is a diagram showing the layout of an electrical switching system, particularly using electromechanical switches, with the select relay 10, the select switch 12, the trigger switch 14, and the arm-safe switch 16, as well as the select lights 18, 20, 22, 24 and the ready lights, 26, 28 in the cockpit of the aircraft A. The contacts 30 and 32, associated with select relay 10, are also within the cockpit.

Two identical sets of switching controls, 34 and 36, are positioned on the right and left pylons, and 6, respectively, to control the arming and tiring two missiles on that pylon.

Throughout FIGS. 4 through 14, a battery symbol 40 represents voltage from a power supply fixed within the aircraft. 43 represents a common ground terminal. Blocking diodes 42 are inserted to prevent the flow of signals in the wrong direction.

In the switching relay FIGS. 4 through 14, letter symbols or letter-number symbols are positioned adjacent relay coils, and they also appear between relay contacts. Like letter symbols or like letter-number symbols refer to the same relay wherein the contacts close upon the energizing of the related coil, or relay winding. When the letter symbol or letter-number symbol between a pair of relay contacts has a line drawn over the symbol or letter-number symbol, it means that the relay contacts associated with that symbol or letter-number symbol are closed when the associated relay coil is not energized and open when the associated relay coil is energized. Thus, for example, a relay coil designated R would be the relay coil for the R relay. A pair of relay contacts having an R between them would close when the relay coil designated R is energized, and a pair of contacts designated R would open when the R relay coil is energized.

Referring to FIG. 4, the turning on of power causes the select switch 30 (not to be confused with the RS- and LS relays) and the arm switch 32 (not to be confused with the ARM relay) to step to its number one position, as shown. The mechanism for causing such initial stepping to the number one position is not shown. With the switches in the position shown, the select light 18 would be lighted. The voltage from voltage source 40, with the switches 30 and 32 in the position shown, is connected to the right pylon electronics 34 to select missile No. 1 which is the left missile on the right pylon.

The arm-safe switch 16 (do not confuse with the arm switch 32 or the ARM relay) when turned to the arm position, applies voltage from voltage source 40 through switch 32 to the right pylon electronics 34, thereby arming missile No. 1.

The switch 12 is mechanically biased into the position shown. When a button is pressed, said button not being shown but usually positioned on the armament control panel of a fighter aircraft, the switch 12 is connected through the select position (not to be confused with select switch 30 nor with the RS or LS relays) to the voltage source 40, thereby causing the relay coil 10 to be energized to index the contactors 30 and 32, upon release of switch 12, to their next consecutive position which, in the position shown, is missile No. 2. Missile No. 2 is the right missile on the left pylon, and the contactors 30 and 32, in position No. 2, are directed to the left pylon electronicscs 36. The selecting by the contactor 30 of missile No. 2 turns on the selected light 20.

With switches 12 and 16 in the position shown the trigger switch 14, in addition to any other control function which it has, indexes the contactors 30 and 32, upon release of switch 14, by energizing the control coil 10.

Referring now to FIG. 4, there are two sets of controls 34 and 36. The detailed switching mechanism of controls 34 or controls 36 are shown in FIGS. 5 through 14. The two sets of controls are identical. It is therefore, unnecessary to repeat the explanation of the structure and operation of the internal mechanization of the two sets of pylon controls 34 and 36, and only one explanation is included herein. For illustrative purposes, it is assumed that the described controls are enclosed on the right pylon.

The switching circuits of FIGS. 5 through 14 mechanize the equations in Table I hereof.

Observe in FIG. 5 that the LS relay closes when the L relay is closed and the RT relay is open whenever switch 30 selects the left missile or when th right missile is selected and the ARM relay is closed.

The RS relay closes when the R relay is closed and the LT relayis open when switch 30 selects the right missile or when the left missile is selected and the ARM relay is closed.

The PS relay closes whenever switch 30 selects a missile on that particular pylon.

Referring to FIG. 6, the R relay closes when the right missile is properly in it launcher and the RSL relay is open.

The L relay closes when the left missile is properly in its launcher and the LSL relay is open.

The RSL relay closes when the RT relay is closed, the right missile is still in its launcher, and three seconds (typically) after the TR signal. Once the RSL relay has closed, it is held closed as long as the right missile remains in its launcher.

The LSL relay closes when the LT relay is closed, the left missile is still in its launcher and 3 seconds has elapsed after the TR relay closes. The LSL relay is held closed as long as the left missile remains in its launcher.

The Q relay closes either three seconds after the closure of the TR relay, or when th PS and B relays are closed the C and ARM relays are open. Once the Q relay is closed, it is held closed until the B relay opens. The capacitor 50, typically, is placed across the coil of the Q relay to cause the Q relay to have a sluggish response.

Referring to FIG. 7, assuming that the described relay is in the right pylon controls, when the switch 32 is in its position No. l or 3, and the TRX relay is open, and either the R relay is open, the L relay is open, the RT relay is closed, or the LT relay is closed, the ARM relay closes.

Referring to FIG. 8, when the trigger switch 14 is actuated, if the switch 16 is in its armed position, and if at least 3 seconds has elapsed after the closing of the B relay, when the PS relay is closed, the TR relay closes.

Referring to FIG. 9 the B relay closes when the Q relay is not closed, the ARM relay is closed, and either the LS or RS relay closes. The B relay is held closed until the Q relay closes.

As shown in FIG. 10, the ready light for the particular pylon is actuated 3 seconds (typically) after the closure of the B relay. The select lights 18 or 22 are closed when the LS or RS relays, respectively, are closed.

Referring to FIG. 11, the C relay closes when the B relay is closed, the Q relay is not closed, and the TR relay closes. The C relay is held closed until either the B relay opens or the Q relay closes.

In FIG. 12, the TRX relay closes one second after the TR relay. The TRX relay is held closed as long as the PS relay remains closed.

In FIG. 13, the RT relay closes with the RS relay. The RT relay is held closed until the B and RS relays open.

Referring to FIG. 14, the LT relay closes with the LS relay. It is held closed until the B and LS relays open.

The time delays are typically caused by timing circuits (not shown). When the B relay closes, arming signals are channeled to the particular missiles depending upon whether the LS or RS relays are closed. If the LS relay is closed, the arming signals are channeled to the left missile; if the RS relay is closed, the arming signals are channeled to the right missile.

Similarly, the closing of the C relay fires the particular missile which is armed. The missile which is armed will have its corresponding select relay, LS or RS, closed which causes the firing signal to be channeled to that missile.

The arming and tiring circuits within the missile are neither part of this invention nor are they shown.

It is desirable to describe the operation of the relays of FIGS. 4 through 14. Assume that all of the power supplies are operating properly, that the aircraft has taken off, the wheels are retracted, and the pilot has turned on the equipment preparatory to its actual operation. Assume further that the initial position of the stepper 110 is to place switches 30 and 32 into the No.

I missile position, although this particular choice is not critical. The select switch 12 is in its shown position, the switch 16 is in its safe position, and the trigger switch 14 is in its open position. The signal through switch 30 is channeled through the circuit of FIG. 5 from the left select terminal, through the top diode 42, and the control coil of the PS relay to the ground terminal 43, thereby closing the PS relay.

Because both the right and left missiles are in place, and because the RSL and LSL relays are not closed, the L and R relays are closed as shown in FIG. 6. The absence of a right select signal as well as the absence of an arm signal prevents the RS relay of FIG. 5 from closing. Because the RS relay is not closed, the RT relay is not closed. Because of the presence of a left select signal, together with the remaining open of the RT relay, and the closure of the L relay, the LS relay of FIG. 5 closes. The closing of the RS relay causes the LT relay (FIG. 14) to close, and it causes the select 18 to light as shown in FIG. 10, indicating that missile No. l has been selected.

The pilot, by successively operating the select switch l2, may step the relay 10 through positions 1, 2, 3, 4, 1 into any position that he desires. If he steps from position 1 to position 2, the PS, RS, and RT relays of the left pylon control switches close, and select lite 20 is lighted.

Further indexing of the stepper switch 10 into its position No. 3 causes the PS, RS and RT signals of the right pylon control switches to appear, and it lights lite 22.

Assume again that the stepper switch 10 is in position No. 1. Assume, further, that all four missiles are on board the aircraft A, and they are connected to be armed and fired. The links 214, 216, 218, and 220 are in place. The selecting of the left missile of the right pylon causes the PS relay of the right control system to close, and the fact that the link 214 is in place and that the left select relay, LSL, has not closed, closes relay L. The closing of relay L, together with the fact that the relay RT has not closed, and the signal from No. 1 step of switch 30 is present causes the LS relay to close. The closing of the LS relay causes the LT relay to close.

Assume, now, that switch 16 is moved from its safe to its armed position. A signal is applied to the arm left input of FIG. 7. The TRX relay has not yet closed, and the LT relay has closed, whereby the ARM relay closes.

The Q relay has not yet closed, and the closing of the ARM relay causes the B relay to close (see FIG. 9). The closing of the B relay, together with the closing of the LS relay causes the No. l missile to commence arming.

The closing of the B relay starts a timer which controls the arming of the left missile. After a 3 second delay (the 3 seconds being merely characteristic of a typical missile) the left or No. 1 missile is armed and ready for firing.

At this point, the pilot has three choices: he may fire the armed missile; he may index to the other pylon and arm a single missile on the other pylon; or he may turn the switch 16 into its safe position, thereby disarming the missile he has just armed.

If the pilot turns his arm-safe switch 16 into its safe position, thereby opening the ARM relay, the fact that the PS relay and B relay are closed, and the C relay is open causes the Q relay to close. The closing of the Q relay is delayed slightly by the capacitance of capacitor 50. The capacitance of capacitor 50 also delays the reopening of the Q relay. The closing of the Q relay causes the B relay to open. The opening of the B relay causes the missile to be disarmed.

If the pilot had decided to fire the armed missile, he would have pressed his trigger switch 14 which would deliver a signal to the circuit of FIG. 8 (the switch 16 is assumed to have remained in its armed position). Provided 3 seconds (typically) has elapsed after the closing of the B relay, the TR relay closes, for the PS relay is already closed. The closing of the TR relay, with the B relay already closed and the Q relay open causess the C relay to close (see FIG. 11). The closing of the C relay, together with the fact that the LS relay is closed, channels a firing signal to the left missile, causing the left missile to fire.

The closing of the trigger switch 14 also causes the stepping switch to step when the trigger 14 is opened. When the trigger 14 is opened, the C relay has already latched, and the firing of the first missile is not disturbed.

When the stepper switch 10 steps to its missile No. 2 position, upon the opening of the trigger switch 14, because the arm-safe switch 16 is still in its armed position, missile No. 2 on the left pylon, through the left pylon controls 36, immediately starts its arming procedure, in a manner identical to that just described for missile No. 1. 3 seconds later (typically) the left pylon ready light turns on, and missile No. 2 is ready to fire.

Suppose that the pilot had decided that he wanted to arm two missile simultaneously so they could be fired in rapid sequence, or ripple fire, without waiting 3 seconds between shots for arming of the second missile. The pilot arms missile No. 1 as described above, but does not operate the trigger 14. Instead, the pilot presses the select switch 12 causing stepper relay 10 to step to position No. 2 upon the release of the select switch 12, where upon missile No. 2, through the control switches 36 on the left pylon, starts to arm missile No. 2 while missile No. 1 is arming or remains armed. It should be noted that the pilot need not wait a full 3 seconds for missile No. 1 to be armed before he presses the select switch 12 as long as the switch 16 remains in its armed position. The fact that switch 16 remains in its armed position almost immediately causes the B relay of the right pylon control system to close. The B relay is latched in until the Q relay closes. The Q relay, in the operation described, does not close until the missile No. 1 is fired and a 3 second delay after the closure of the TR relay, or the arm-safe switch 16 is moved to the safe position while a right pylon missile is simultaneously selected. Note that the cycling of stepper 10 opens the PS relay in the right control system, thereby opening the ARM relay. The removal of the ARM relay in the right controls does not cause the B relay to open because of the feedback in the control loop of the B relay. The delay, due to the fact that the stepper 10 does not step until the selector 12 is released, prevents the Q relay from closing. Thus, the pilot may switch to the No. 2 missile position of steper 10 by pressing the select switch 12, starting arming of missile No. 2 before the missile No. 1 is fully armed.

With missiles Nos. 1 and 2 arming or armed, the pilot may not arm missiles Nos. 3 and 4 before missile 1 and missile 2, respectively, are either fired or disarmed Suppose that missiles No. 1 and 2 are either armed or arming. If the pilot again presses select switch 12, thereby stepping steper 10 into its No. 3 position, the PS relay, of the right pylon controls, closes. Neither of the missiles on the right pylon have been fired, whereby the RSL relay remains open. Since the right missile is still in place, the R relay is closed. Remembering that missile No. 1 is either armed or arming, the B relay is closed which holds the LT relay closed. Consequently the RS relay may not now reclose. Because the RS relay will not close, the right missile will not be armed even if the ARM relay closes, for the circuitry of FIG. 5 requires the closing of the RS relay before missile No. 3 will commence arming. In fact, because the B relay remains closed, the LT relay (see FIG. 14) remains closed. Because the No. 1 missile not been fired, the TRX relay has not closed. The arm right signal from switch 32 causes the ARM relay to close (see FIG. 7). The closing of the ARM relay causes the right select signal (see FIG. 5) to be channeled to close the LS relay. The LS relay, then, remains closed, whereby when the trigger switch is closed, thereby closing the C relay, the left missile rather than the right missile is fired. The opening of the trigger switch 14 causes the stepper switch 10 to index to its No. 4 position and, by operation of the left pylon controls in a manner similar to that just described for the right pylon controls, although the No. 4 missile is a left missile, the left select signal is channeled to close the RS relay in the left pylon controls, thereby firing missile No. 2 when the trigger 14 is next closed.

It should be noted that the pilot did not have to index back to positions No. 1 and 2 to fire the missiles No. 1 and 2 in rapid sequence. In fact, he could start the firing at any position of relay 10.

As soon as the trigger 14 is removed from the firing for No. 4 missile, (which actually fired No. 2 missile), stepper 10 indexes the stepper switch into the No. 1 missile position. It should be noted, however, that missiles No. 1 and 2 have been fired. Accordingly, the L relay on the right pylon controls and the R relay on the left pylon controls remain open.

With the switch 16 remaining in the armed position, when switch 30 moves into its No. 1 position, the PS relay is closed. The TRX relay (see FIG. 12) has closed and reopened. Switch 32 places the signal on the arm left terminal which actuates the ARM relay because the L relay is open. The right missile remains in position, whereby, provided the RSL relay is open, the R relay is closed. The LT relay is opened, whereby the left select signal closes the RS relay. The ARM relay closure closes the B relay, and the RS relay channels the signal from the B relay to the No. 3 missile (although switches 30 and 32 are in the Number 1" missile position). The RS relay closure closes the RT relay which remains closed until the B relay re-opens; (See FIG. 13.) When the trigger switch 14 is closed, the trigger signal is delivered to close the TR relay (provided at least three seconds has elapsed since the closure of the B relay) (see FIG. 8). The C relay, since the Q relay has not closed, closes upon the closure of the TR relay and is held until either B relay opens or the Q relay closes. The fact that the LT relay is open while the R relay is closed, and the ARM relay is held closed by the presence of an arming signal together the closure of the RT relay, causes the RS relay to remain closed after the trigger and after the C relay latches, whereby the right missile is automatically fired.

In a similar fashion, the No. 4 missile may be armed when the stepper relay turns to its No. 2 position because the No. 2 missile is no longer there and the control system of the left pylon causes the No. 2 signals to generate a LS signal in the control system 36.

Further, instead of firing the No. 3 missile when the stepper 10 was in its No. 1 position, the pilot might have pressed the select switch 12 which would step the stepper 10 into its No. 2 position thereby commencing the arming of the No. 4 missile. When the trigger was next actuated, the N0. 4 missile would have been fired first, and after a short delay due to the fact that the stepper 10 does not step until the trigger 14 is opened, the stepper 10 would have stepped to the No. 3 missile position. The next pull of the trigger would have fired the No. 3 missile.

The LSL and RSL relays are designed into the system to lock out the closing of the LS and RS relays. The LSL relays close three seconds (typically) after the closure of the TR relay, provided their associated missile is still in place at that time. Thus, the LSL and RSL relays could be called hang fire relays if desired. Assuming that the left missile was the missile to be fired first, the LT relay is closed which causes the 3 second delayed signal from TR relay to close the LSL relay because the left missile is still in place. The LSL relay then remains closed as long as the left missile remains in place. The LT relay stays on momentarily after the 3 second delay time. The brief delay is caused, for example, by the capacitor across the coil of the Q relay, whereby the Q relay, and consequently and B and LT relays are not opened until a short time after the LSL relay is closed.

Similarly, if it had been the right missile which had been recently fired, the RT relay would be closed and the delayed TR signal would close the RSL relay if the right missile had failed to leave its launcher. The closure of the LSL or RSL relays, respectively, prevent the closure of the L and R relays and consequent closure of the LS and RS relays.

The Q relay remains closed only momentarily. The pilot holds his trigger for only a short time. That short pulse is then transmitted, after delay, for example three seconds, to close the Q relay. The closing of the Q relay opens the B relay which opens the C relay thereby opening the Q relay.

The TRX relay is closed by the closure of the TR relay delayed, for example, by 1 second. The closure of the TRX relay prevents the arming and firing of a second missile on the same pylon if the pilot neglects to release his trigger 14. Note, for example, that the TRX relay must be open before the ARM relay may close. Thus, one second after the TR relay closes, not only the TRX relay closes, but also the ARM relay opens. The TRX relay is then held closed by the PS relay until the stepper 10 makes a step to a position corresponding to a missile on the other pylon, at which time the PS relay opens and so does the TRX relay, allowing the ARM signal to reappear the next time a missile on that particular pylon is selected.

Thus, there has been presented an automatic missile arming and firing system, particularly adapted to arm a single missile at a time on each of a plurality of launching stations such as the missile pylons of an aircraft.

The system of this invention automatically compensates for the absence of a missile from its launcher and automatically transfers arming and firing signals to the remaining rocket upon that particular pylon. Further, the consecutive arming and firing in a ripple-fire mode is facilitated.

The described invention also has the features of preventing double fire and preventing the arming and/or firing of a missile which has previously failed to fire.

Although the invention has been described in detail above, it is not to be limited by that description, but only in accordance with the spirit and scope of that specification taken together with the appended claims.

We claim:

1. On a vehicle having a plurality of missile launching pylons, each supporting a plurality of missile launchers, some of said launchers having missiles thereon of the type which require that an arming signal be applied a preselected time interval before launching, a control system for delivering arming and firing signals to said missiles, comprising:

substantially identical control circuits on each pylon;

a sequencer for delivering select signals consecutively to different ones of said missiles, said sequencer being operatively connected to assure that consecutively selected missiles are on different pylons;

means for producing arming signals, and for directing them through said sequencer to the control circuit upon the selected pylon which corresponds to the selected missile;

means for delivering firing signals to said control circuits at said pylons; and

wherein said control circuit upon said selected pylon includes means for ensuring that only one missile at each pylon may be armed at any one time, means for delivering said arming signal to an alternate missile when said selected missile is not in its launcher, means for delivering said arming signal to an alternate missile when said selected missile has previously had a firing signal applied thereto and had failed to launch, and means for delivering said firing signals only to missiles which have had an arming signal applied thereto for at least said preselected time interval.

2. The apparatus as recited in claim 1 further comprising means for disarming an armed missile upon said selected pylon if after a preselected period following the application of a firing signal thereto, said armed missile had not been lanuched.

3. Apparatus for controlling the arming and firing of a plurality of missiles of the type which require that an arming signal be applied a preselected time interval prior to firing, said missiles being mounted upon a pluraltiy of pylons upon a vehicle, and said apparatus com prising:

means for consecutively delivering arming signals to one missile mounted upon each of said pylons, said delivering means including means for redirecting said arming signal to an alternate missile on said pylon when said selected missile is not in firing position, and means for inhibiting the delivery of arming signals to a missile which had previously had a firing signal applied thereto and has failed to launch;

means for delivering firing signals consecutively to each of said missiles to which an arming signal had 22 means for selectively disarming previouly armed missiles.

4. The apparatus of Claim 3 wherein said means for selectively disarming previously armed missiles includes means for disarming an armed missile if after a preselected period following the application of a firing signal thereto, said missile had not been launched. 

1. On a vehicle having a plurality of missile launching pylons, each supporting a plurality of missile launchers, some of said launchers having missiles thereon of the type which require that an arming signal be applied a preselected time interval before launching, a control system for delivering arming and firing signals to said missiles, comprising: substantially identical control circuits on each pylon; a sequencer for delivering select signals consecutively to different ones of said missiles, said sequencer being operatively connected to assure that consecutively selected missiles are on different pylons; means for producing arming signals, and for directing them through said sequencer to the control circuit upon the selected pylon which corresponds to the selected missile; means for delivering firing signals to said control circuits at said pylons; and wherein said control circuit upon said selected pylon includes means for ensuring that only one missile at each pylon may be armed at any one time, means for delivering said arming signal to an alternate missile when said selected missile is not in its launcher, means for delivering said arming signal to an alternate missile when said selected missile has previously had a firing signal applied thereto and had failed to launch, and means for delivering said firing signals only to missiles which have had an arming signal applied thereto for at least said preselected time interval.
 2. The apparatus as recited in claim 1 further comprising means for disarming an armed missile upon said selected pylon if after a preselected period following the application of a firing signal thereto, said armed missile had not been launched.
 3. Apparatus for controlling the arming and firing of a plurality of missiles of the type which require that an arming signal be applied a preselected time interval prior to firing, sAid missiles being mounted upon a plurality of pylons upon a vehicle, and said apparatus comprising: means for consecutively delivering arming signals to one missile mounted upon each of said pylons, said delivering means including means for redirecting said arming signal to an alternate missile on said pylon when said selected missile is not in firing position, and means for inhibiting the delivery of arming signals to a missile which had previously had a firing signal applied thereto and has failed to launch; means for delivering firing signals consecutively to each of said missiles to which an arming signal had been applied after said preselected time interval has elasped since the application of an arming signal to each of said missiles, and said means for delivering including means for redirecting said firing signal to the particular missile on said pylon which is armed; means for delivering arming signals to a second missile upon each of said pylons after said previously armed missile has been fired; and means for selectively disarming previouly armed missiles.
 4. The apparatus of claim 3 wherein said means for selectively disarming previously armed missiles includes means for disarming an armed missile if after a preselected period following the application of a firing signal thereto, said missile had not been launched. 